Why not use the published figures?
The best independent study found click-through roughly halves when an AI summary is present (Pew Research Center, 2025). That’s a strong signal about the market. It isn’t a measurement of your site, your queries or your audience, and a budget decision deserves that.
What does the comparison show?
How much of your demand now sits under an AI answer, and the difference in click-through between those searches and the rest. Together they size the problem in your own terms: how much traffic is exposed, and what it’s costing.
What does it not show?
Why any single search lost its click, or what would happen if you were cited. It measures the gap. It doesn’t forecast what closing it would earn, and it isn’t presented as if it did.
What should a team do with it?
Decide where to aim. Searches with an AI answer and a large click gap are where AIO ranking matters most; searches without one are where classic ranking work still pays directly.